This proposal is to continue ongoing research aimed at understanding cross-modal interactions between touch and vision, using psychophysical and functional neuroimaging studies in normally sighted and blind individuals. The long term objective is to expand knowledge of multisensory processing and the plasticity of the underlying neural mechanisms, with a view ultimately to devising novel neuro-rehabilitative approaches in a variety of contexts, including blindness. Specific Aim I investigates shared neural processing of tactile and visual features and objects while Specific Aim II explores how visual deprivation alters processing of tactile features and objects. These two aims test the hypotheses that (A) tactile and visual perception of features and objects both recruit similar cortical regions and that involvement of multisensory and visual cortical areas during tactile perception is associated with visual imagery; and (B) involvement of multisensory and visual cortical areas and the functional and effective connectivity of these areas with somatosensory cortical areas during tactile perception is enhanced by visual deprivation, especially that associated with congenital blindness. Specific Aim III explores the functional consequences of shared processing between vision and touch, testing the hypothesis (C) that multisensory integrative processing of visual and tactile information takes place in higher-order multisensory areas, such as posterior parietal cortex, with associated increases in functional and effective connectivity with unimodal areas. The methods used in the proposed research are both psychophysical and neuroimaging {using functional magnetic resonance imaging, fMRI). An important aspect of these studies is that we will seek correlations between imaging and psychophysical data in an attempt to better understand the relationship between brain and behavior. The studies proposed in this application will enhance our knowledge of interactions between vision and touch in normal humans and the effects of visual deprivation on these interactions. Specifically, they will extend our understanding of the engagement of visual and multisensory cortical areas during tactile perception in normally sighted and visually deprived individuals, the role of mental imagery in such engagement and the nature of multisensory processing and integration. The findings of the studies will impact not only our appreciation of normal multisensory interactions but also of changes resulting from permanent visual deprivation arising at birth or after early childhood. In the long term, these studies will be relevant to the design of novel interventions aimed at improving the functional integration of those with sensory deprivation into society as well as more general approaches to neurological rehabilitation.